The subject invention concerns sheet-laminating machines designed to align two or more sheets to form a multiply sheet and comprising one upper and one lower sheet-deposit unit for positioning respectively top and bottom sheets, means for application of glue to the upper face of the bottom sheet, means for registering the sheets, presser means and a discharge unit.
In uniting sheets by machine as outlined above it is necessary that the sheets are carefully aligned and in register since otherwise printed articles, such as cardboard boxes and the like, made from the superposed and united sheets, after punching may take on an unacceptable appearance on account of poor registering. Problems may also arise when a thick sheet is to be laminated with a thinner one, since in such cases the two sheets usually react differently to the moisture to which they are exposed from the glueing, which may result in bulging or warping. Bulging or warped sheets may cause problems in e.g. punching machines.
Because of the requirements on alignment and even-levelness of superposed sheets prior-art sheet-laminating machines are comparatively large and expensive devices which usually include several micro-switches or photoelectric cells as well as pneumatically driven means.
The purpose of the subject invention is to provide a sheet-laminating machine designed for automatic superposing of sheets in aligned relationship. The machine comprises a smaller number of parts than conventional machines of this kind. Consequently, the machine is cheaper to manufacture and to run and is less noisy.